What Happens to Your Immune System as You Age?

What Happens to Your Immune System as You Age?

Everything about your body changes to some degree as you age. Some of these changes are desirable. For example, you’re wiser than you were 20 years ago, while others you could do without. It’s not just your outward appearance that undergoes a transition, cells and tissues age as well, including your immune system.

Your immune system is probably not something you think about, but it’s constantly at work protecting you from foreign invaders – from viruses and bacteria to tumor cells. With such an important job, keeping your immune system healthy helps keep YOU healthy. So, you want it to do its job at all ages. What changes happen to your immune system as you age?

The Two Divisions of Your Immune System

Your immune system is made up of an innate division and an adaptive division. The innate portion of is made up of cells and physical barriers, like your skin and mucous membranes, that protect against invaders. For example, your mucous membranes release chemicals that help eradicate bacteria and viruses. Your skin acts as a physical barrier to foreign invaders, making it harder for them to gain access to your body. Plus, you have certain cells, such as natural killer cells and macrophages, that are on the frontlines ready to react to a threat. These are defenses that you’re born with and they’re non-specific. They’re ready to tackle any potential pathogen or threat, even if they’ve never encountered it before.

In contrast, the acquired portion of your immune system is made up of specialized cells and proteins that acquire the ability to protect against invaders. They act as a more sophisticated back-up system when the innate immune system can’t eradicate a threat on its own. Cells in the acquired immune system have “memory.” Once they make contact with a particular foreign invader or foreign protein, they can recognize it again and launch an attack against it. Therefore, these cells are trained to identify a specific threat, making them specialized. The acquired immune division includes various types of T-cells and B-cells that produce antibodies.

Your Immune System Becomes Less Efficient with Age

Unfortunately, both divisions of the immune system become less efficient with age. The decline in immune function that goes along with aging is called immunosenescence. Of the two parts of the immune system, it’s the adaptive immune response that declines the most. Evidence of a drop in adaptive immunity is evident in the way the body responds to a vaccine later in life.

A vaccine consists of an attenuated virus (one that’s too weak to cause illness) or a synthetic protein that resembles that virus. When you introduce the vaccine into the body, it elicits an immune response and creates T-cells and B-cells. These cells are trained to recognize that virus should they encounter it again. People over the age of 60 don’t mount as robust of an immune response when vaccinated and the protection against infection is often weaker. Due to weakening of the immune response, older people are at higher risk of infection and infections are often more severe.

In addition, B-cells, the cells that produce antibodies decrease in number with age and T-cells do too. T-cells are made by the thymus gland, a gland in your chest, and it becomes atrophic later in life. The innate immune system doesn’t escape aging either. Natural killer cells, the cells that are geared up to fight viruses and early cancer cells, decrease in number, making it easier for cancer and viral infections to gain a foothold.

Age-Related Low-Grade Inflammation

You might think that if the immune response decreases, inflammation would go down. After all, inflammation is over-activity of the immune system and the immune system becomes less responsive to threats with age. Paradoxically, inflammation increases with age – what you’re actually getting is immune dysfunction rather than simply suppression of the immune system. After menopause, there’s a sharp rise in autoimmune disease in women, due to production of antibodies against normal tissues. The immune system seems to fire up inappropriately at times and yet be less effective when there’s a legitimate threat.

How does all of this come about? Studies show that immune cells of older adults produce higher levels of pro-inflammatory chemicals called cytokines. One in particular called IL-6 goes up with age. Over time, the pro-inflammatory effects of these cytokines can damage healthy tissues. Experts believe this type of damage contributes to aging and age-related diseases. In fact, in recent years, a new term has been coined to describe this phenomenon – inflammaging.

It’s a Double-Edged Sword

As you can see, immune systems change with age and they are altered in more than one – susceptibility to infection increases AND tissue damage due to immune system over-activity goes up as well. That’s why autoimmune diseases are more likely to strike after menopause in women and death due to infection is more common after the age of 65. Is there anything you can do to avoid these problem or at least lower your risk?

Ways to Reduce Age-Related Changes in Immune Function

· Check your vitamin level of ensure you’re within the optimal range. Vitamin D is a modulator of immune function.

· Eat a balanced diet with lots of plant-based foods. Plant-based foods contain vitamin C, a vitamin linked with healthy immune function. They’re also a good source of immune-protective antioxidants.

· Avoid processed foods. They are rich in processed omega-6 fats that create a pro-inflammatory environment.